Rh(I)-Catalyzed 1,4-Conjugate Addition of Alkenylboronic Acids to a Cyclopentenone Useful for the Synthesis of Prostaglandins

An efficient and <i>trans</i>-diastereoselective Rh­(I)-catalyzed 1,4-conjugate addition reaction of alkenylboronic acids and a homochiral (<i>R</i>)-4-silyloxycyclopentenone useful for the synthesis of derivatives of prostaglandins E and F is described for the first time. The reaction functions under mild conditions and is particularly rapid (≤6 h) under low power (50 W) microwave irradiation at 30 °C in MeOH in the presence of a catalytic amount of KOH. Under these conditions, 3 mol % of [RhCl­(COD)]₂ is typically required to produce high yields. The method also functions without microwave irradiation at 3 °C in the presence of a stoichiometric amount of KOH. Under these conditions, only 1.5 mol % of [RhCl­(COD)]₂ is needed, but the reaction is considerably slower. The method accepts a range of aryl- and alkyl-substituted alkenylboronic acids, and its utility has been demonstrated by the synthesis of PGF_2α (dinoprost) and tafluprost

Enantioselective and Rapid Rh-Catalyzed Arylation of <i>N</i>‑Tosyl- and <i>N</i>‑Nosylaldimines in Methanol

Enantiomerically enriched tosyl-protected diarylmethylamines were rapidly prepared by the asymmetric addition of arylboronic acids to <i>N</i>-tosylaldimines under mild conditions in the presence of a catalyst prepared in situ from Rh­(I) and a chiral diene ligand. This methodology offers access to diarylmethylamines in good yields with excellent chiral purity at room temperature using MeOH as a solvent and NEt₃ as a base. Its synthetic utility was demonstrated by the preparation of (S)-1-phenyl-1,2,3,4-tetrahydroisoquinoline (<b>14</b>), an antagonist of the <i>N</i>-methyl-d-aspartate (NMDA) receptor

Enantioselective and Rapid Rh-Catalyzed Arylation of <i>N</i>‑Tosyl- and <i>N</i>‑Nosylaldimines in Methanol

Enantiomerically enriched tosyl-protected diarylmethylamines were rapidly prepared by the asymmetric addition of arylboronic acids to <i>N</i>-tosylaldimines under mild conditions in the presence of a catalyst prepared in situ from Rh­(I) and a chiral diene ligand. This methodology offers access to diarylmethylamines in good yields with excellent chiral purity at room temperature using MeOH as a solvent and NEt₃ as a base. Its synthetic utility was demonstrated by the preparation of (S)-1-phenyl-1,2,3,4-tetrahydroisoquinoline (<b>14</b>), an antagonist of the <i>N</i>-methyl-d-aspartate (NMDA) receptor